At plants, factories, and such like, it is conventional to construct a distributed control system (DCS), in which devices known as field devices (measuring devices, manipulating devices, etc.) for achieving a high degree of automatic operation, and a control device for controlling them, are connected via a communication means. While most such distributed control systems use wire communication, recently, some are being realized using wireless communication that is compliant with wireless communication standards for industrial automation, such as ISA100.11a and WirelessHART (Registered Trademark).
The distributed control system that performs wireless communication compliant with the wireless communication standards for industrial automation mentioned above broadly includes field devices capable of wireless communication (wireless field devices), a wireless access point device, a control device, and a system manager. The wireless access point device is connected to the control device and the system manager via a communication line, installed at a position where it can perform wireless communication with the wireless field devices, and relays various types of data that are transmitted and received between the wireless field devices and the control unit. The control unit controls the wireless field devices by transmitting and receiving various types of data (e.g. measurement data and control data) to and from them via the wireless access point device.
The system manager manages and controls resources such as the frequency channel, communication schedule, and communication path of the wireless communication network formed by the wireless access point device and the wireless field devices, and thereby manages and controls the wireless communication performed via the wireless communication network. The non-patent document 1 discloses one example of a control system capable of wireless communication compliant with ISA100.11a.